you asked about light, LED?
get this app
Professional light intensity (lux) meter for your android device.
play.google.com
Clones and seedlings: 2,000–4,000 lux and doesnt matter so much
Vegetative growth: 15,000–30,000 lux start at 20, watch plant. you are looking for leaves pointed up "praying"
Flowering: 45,000–110,000 lux the upper end needs co2. try starting at 65,000, watch and adjust
as for how high, try this (this is REAL wattage, so on an led look at actual wattage, an led that says 1000 is normally only 100w maybe 150w. no real standard.
- 5” to 11” for 150W lights
- 6” to 13” for 250W lights
- 8” to 19” for 400W lights
- 9” to 25” for 600W lights
- 11” to 31” for 1,000W lights
the key to it all is to spend the time watching them and adjust as they tell you